This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Nano-scaled materials play a very important role in both scientific and applied areas. Though much progress has been made in nano-science, the investigation of nanomaterials'growth is still great challenge. In this project, we are using single crystals of lysozyme to slow down the growth of metal nanoparticles and thus study their growth kinetics at the molecular level. Lysozyme was chosen for this project because it not only can be readily crystallized, but also has a unique surface-exposed His at position 15 as a specific binding site for metal ions. Our primary results showed that lysozyme crystals could slow the reaction and thus we could get the snapshots of the interactions between lysozyme and the metal ions by X-ray crystallography. With the help of other techniques (such as transmission electron microscopy), we will elucidate the reaction mechanism of metal nanoparticles'growth within the lysozyme crystals, which might have implications in fabrication of bio-nano hybrid materials, biomineralization, catalysis, optical and plasmonic devices, and sensing.